drop deprecated annotations `ref` in v3

[archmoj]

plotly.js/src/components/annotations/attributes.js

Lines 491 to 499 in 206d117

	_deprecated: {
	ref: {
	valType: 'string',
	editType: 'calc',
	description: [
	'Obsolete. Set `xref` and `yref` separately instead.'
	].join(' ')
	}
	}